Rotary ejector compressor

ABSTRACT

Method and apparatus for a compressor for compressing air, gases and vapors approximately isothermally by using a liquid stream to entrain and compress the gas; with the liquid being accelerated by an impeller, inner passage, and the gas initially being accelerated by vanes placed on the outside of the same impeller; the two streams are brought together and compressed by using the kinetic energy contained in the liquid stream. Further, the compressor can advantageously be used to compress vapors where the gas stream is condensed fully or in part by the liquid stream thereby decreasing the specific volume of the total fluid stream during compression, and improving the efficiency of the compression.

United States Patent 1 1 [111 3,719,434 Eskeli 1 1 March 6, 1973 [5 ROTARY EJECTOR COMPRESSOR 26,368 11/1907 Great Britain ..415/98 962 11/1915 Netherlands... ....417/161 [76] Invent g xg gi 22 83 534,260 9/1931 Germany ..4l5/98 [22] Filed: March 30, 1971 Primary Examiner-Henry F. Raduazo 1 pp No 129 407 AttorneyWofford, Felsman & Fails [57] ABSTRACT [52] U.S.Cl. ..417/78,4l5/98, 4411576211611, Method and apparatus for a compressor for pressing air, gases and vapors approximately isothergfi/ P mally by using a liquid stream to entrain and compress FOREIGN PATENTS OR APPLICATIONS 6/1935 Great Britain ..417/78 the gas; with the liquid being accelerated by an impeller, inner passage, and the gas initially being acceleratedby vanes placed on the outside of the same impeller; the two streams are brought together and compressed by using the kinetic energy contained in the liquid stream. Further, the compressor can advantageously be used to compress vapors where the gas stream is condensed fully or in part by the liquid stream thereby decreasing the specific volume of the total fluid stream during compression, and improving the efficiency of the compression.

6 Claims, 3 Drawing Figures PATENTEDHAR 61m 3,719,434

SHEET 10F 2 IN VENTOR.

BY WW M PATENTEU W 6 I975 SHEU 2 OF 2 FIG I BY MM 410.4.

IN VEN TOR.

ROTARY EJECTOR COMPRESSOR BACKGROUND OF THE INVENTION This invention relates generally to devices for compressing gases or vapors in which a liquid fluid is in intimate contact with the gas or vapor to be compressed during compression.

DESCRIPTION OF PRIOR ART There are numerous devices and machines available for compressing a gas or a vapor. In some of these machines a liquid is rotated inside an eccentric casing causing the liquid to pulsate and compress the gas; these are usually referred to as liquid piston compressors. Another device is the jet ejector compressor, where a high velocity fluid stream is used to compress a gas or a vapor.

The main disadvantage of the liquid piston type machine is its poor efficiency due to the liquid being circulated in the machine casing requiring large amounts of power. In the ejector compressor, when liquid is used as the motive fluid, the velocity of the liquid stream is limited in the motive fluid nozzle by the nature of the device, and further entrainment of the gas by the liquid is poor in many instances, reducing the efficiency of the device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exterior view of the compressor casing,

DESCRIPTION OF PREFERRED EMBODIMENTS It is an object of this invention to provide a method and a device for compressing gases or vapors in which the kinetic energy contained in a fluid stream is used to compress said gas or vapor to a higher pressure. Also, it is an object of this invention to provide a method and a device where the gas or vapor to be compressed may be either partly or fully be condensed in the high velocity fluid stream during compression thereby decreasing the required work of compression.

Referring to FIG. 1 there is shown an end view of the compressor. is the compressor casing, 11 is the fluid outlet from the compressor, 12 is the gas or vapor inlet to the compressor, 13 is the liquid motive fluid inlet to the impeller, 14 is an annular space to which the compressed fluid is collected, 15 is one of the vanes in the compressing passage, 16 is the impeller with its vanes for the initial acceleration of the gaseous fluid.

In FIG. 2, a side view of the compressor is shown. 10 is the compressor casing, 18 is the shaft seal, and 19 is the impeller shaft.

In FIG. 3, a cross section of the compressor is shown. 10 is the compressor casing, 11 is the outlet for the compressed fluid, 12 and 25 are the two inlets for the suction fluid, 13 is the liquid motive fluid inlet, 14 is the annular space for collecting the fluid after compression, 16 is the impeller, 18 is the shaft seal, 19 is the impeller shaft, 21 is the passage where the fluid is compressed and the kinetic energy contained in the fluid mixture is converted to pressure, 15 is the vane in the passage 21, 24 is the mixing area where the two fluid streams are brought together, 22 indicates the vanes on the exterior of the impeller used to initially accelerate the gaseous portion of the fluid to be compressed, 23 indicates the passage for the liquid portion of the fluid with suitable vanes, and 26 and 27 are two spaces for passing through the gaseous portion of the fluid.

The function of the compressor is as follows. Liquid fluid is passed to the center of impeller, 16 in FIG. 3. The liquid is accelerated in the impeller by centrifugal action, and by a pressure differential, since the liquid fluid normally is coming from the receiver-separator where the pressure is the same as at the outlet of the compressoLAlso, with certain fluids, where the fluid in the reservoir is a saturated liquid with saturated vapor in the upper part of the said reservoir, the liquid fluid in the impeller is partially vaporized and this vaporization further accelerates said fluid in the impeller passage 23, FIG. 3. The gaseous or vapor fluid entering the compressor through openings 12 and 25, is passed to the external vanes of the impeller and there accelerated; this acceleration will improve entrainment of the gas in the motive fluid in the mixing area 24 and also provide some initial velocity for the gas and thus decrease the shock in the motive fluid stream which a stationary gas would impose. After mixing, the fluid stream is compressed in the passage 21, with a corresponding decrease in velocity. After collection of the fluid in space 14, the fluid is passed to a reservoir-separator through opening 1 1.

The passages in the impeller, 23, must be so designed that the rotational energy available from the impeller, and the pressure energy available in the liquid, and the energy available due to possible gasification of the liquid in the passage, are all converted to a velocity energy at the passage outlet.

As illustrated in FIGS. 1 and 3, the passages 23 comprise a converging section nearest the center of the impeller but are at least non-converging at the discharge section. Preferably, the at least non-converging section is a diverging section for better taking advantage of the energy available in a saturated liquid motive fluid to effect higher effluent velocities thereof at a substantially continuous peripheral discharge passage of the impeller. Similarly, the passage in the stationary casing, 21, must be so designed that the kinetic energy in the fluid stream is converted to pressure. As also illustrated in FIGS. 1 and 3, the passageways 21 intermediate the vanes 15 are similarly at least non-converging, and preferably diverging. These calculations are not detailed herein, since they are available in various textbooks on fluid mechanics and on jet ejector compressors.

The compressor may be used to compress gases, such as air, by using a liquid, such as water, as the motive fluid. Alternately, a vapor, such as propane, may be compressed using as the motive fluid propane liquid. Normally, the amount of liquid as compared to gas, is large, and in the case, such as air, the compression is approximately isothermal, resulting in a lower work of compression. Where the same fluid is used both as the motive and the suction fluid, liquid and vapor respectively, the vapor is partially condensed in the liquid, resulting in a lower work of compression and improved efficiency.

The operation of the compressor may be inferred from the above descriptive matter. A liquid source is connected to the impeller inlet, and a gas or vapor source connected to the gas inlet. Discharge from the compressor is through the discharge opening. A suitable power source, such as an electric motor, is connected to the compressor shaft, causing it to rotate in suitable direction. The liquid is accelerated by the impeller, by the pressure differentials within the impeller and by possible vaporization of the liquid fluid. After leaving the impeller, the gaseous fluid and the motive fluid are mixed, and then compressed in the stationary part of the compressor, and then discharged from the compressor.

Further, the said compressor may be built into a pressure vessel or a tank, with the impeller liquid suction from such tank directly. In such arrangement, the annular space 14, FIG. 3, may be omitted, with the compressor discharging directly to the said tank. The gas suction 25, FIG. 3, may open through the tank wall to outside and a suitable conduit connected through the tank wall to opening 12.

What is claimed is: 1. A machine for compressing gaseous fluid and comprising:

a. an impeller for accelerating a liquid motive fluid to a high velocity; said motive fluid comprising at the entry to the impeller a liquid; said impeller having fluid passages that comprise respective initially converging sections as the passages extend outwardly from the center of said impeller and at least non-converging sections extending radially exteriorly of said converging sections; said plurality of non-converging sections defining a substantially continuous discharge passage of said impeller for continuous flow of said motive fluid therefrom and for more effective use of the available energy of said motive fluid which has been accelerated to a high velocity such that said motive fluid may be partially vaporized at the decreasing pressure due to said at least non-converging passages and said high velocity to attain even higher velocities for more effective entrainment of said gaseous fluid; and being designed to convert to velocity, of said motive fluid, energy due to centrifugal action of the rotating impeller and also energy due to pressure differential between the impeller inlet and the impeller outlet;

b. a casing disposed about said impeller; said casing having a centrally disposed chamber defined about said impeller for receiving said gaseous fluid; said chamber extending radially outwardly concurrently with said impeller; an inlet port connected with said chamber for intake of said gaseous fluid; a mixing section connected with the circumferential portion of said chamber and encompassing the discharge passage of said impeller for entraining said gaseous fluid from said chamber into the effluent stream of said motive fluid which has unusually high velocity and unusually high efficiency of entrainment as a consequence of its acceleration by said impeller; said casing having a suitable compressing passage providing for the compression and deceleration of the combined fluid stream after said motive fluid leaves said impellet, suitable vanes being provided in said compressing passage to prevent circular motion of said fluid in said compressing passage and to improve compression performance; said casing being provided with inlet and outlet ports, respectively, for connection of suitable respective conduits for the intake of said motive fluid and for the discharge of said compressed gaseous fluid and said motive fluid; and

c. a shaft to support said impeller, said shaft having a shaft seal.

2. The machine of claim 1 wherein the impeller motive fluid passages are diverging to provide for acceleration of the motive fluid due to partial vaporization of said motive fluid in said impeller fluid passages.

3. The machine of claim 1 wherein the mixing section and the compressing passages in the casing containing the vanes, are made a converging-diverging passage .with the position of the vanes being adjustable to provide for optimum performance.

4. The machine of claim 1 wherein said machine is used as a vacuum pump.

5. The machine of claim 1 wherein gas acceleration vanes are provided on the outer surface of said impeller intermediate said impeller and the interior walls of said chamber for accelerating said gaseous fluid and for providing an initial velocity to said gaseous fluid so as to move it in the same direction that said motive fluid is moving such that the entrainment of said gaseous fluid is enhanced for improved efficiency in compressing said gaseous fluid by said high velocity motive fluid from said impeller.

6. The machine of claim 1 wherein the compressor is buil into a pressure vessel, with the impeller suction being from said vessel, and the compressor discharge being directly to said pressure vessel. 

1. A machine for compressing gaseous fluid and comprising: a. an impeller for accelerating a liquid motive fluid to a high velocity; said motive fluid comprising at the entry to the impeller a liquid; said impeller having fluid passages that comprise respective initially converging sections as the passages extend outwardly from the center of said impeller and at least non-converging sections extending radially exteriorly of said converging sections; said plurality of non-converging sections defining a substantially continuous discharge passage of said impeller for continuous flow of said motive fluid therefrom and for more effective use of the available energy of said motive fluid which has been accelerated to a high velocity such that said motive fluid may be partially vaporized at the decreasing pressure due to said at least non-converging passages and said high velocity to attain even higher velocities for more effective entrainment of said gaseous fluid; and being designed to convert to velocity of said motive fluid, energy due to centrifugal action of the rotating impeller and also energy due to pressure differential between the impeller inlet and the impeller outlet; b. a casing disposed about said impeller; said casing having a centrally disposed chamber defined about said impeller for receiving said gaseous fluid; said chamber extending radially outwardly concurrently with said impeller; an inlet port connected with said chamber for intake of said gaseous fluid; a mixing section connected with the circumferential portion of said chamber and encompassing the discharge passage of said impeller for entraining said gaseous fluid from said chamber into the effluent stream of said motive fluid which has unusually high velocity and unusually high efficiency of entrainment as a consequence of its acceleration by said impeller; said casing having a suitable compressing passage providing for the compression and deceleration of the combined fluid stream after said motive fluid leaves said impeller, suitable vanes being provided in said compressing passage to prevent circular motion of said fluid in said compressing passage and to improve compression performance; said casing being provided with inlet and outlet ports, respectively, for connection of suitable respective conduits for the intake of said motive fluid and for the discharge of said compressed gaseous fluid and said motive fluid; and c. a shaft to support said impeller, said shaft having a shaft seal.
 1. A machine for compressing gaseous fluid and comprising: a. an impeller for accelerating a liquid motive fluid to a high velocity; said motive fluid comprising at the entry to the impeller a liquid; said impeller having fluid passages that comprise respective initially converging sections as the passages extend outwardly from the center of said impeller and at least non-converging sections extending radially exteriorly of said converging sections; said plurality of non-converging sections defining a substantially continuous discharge passage of said impeller for continuous flow of said motive fluid therefrom and for more effective use of the available energy of said motive fluid which has been accelerated to a high velocity such that said motive fluid may be partially vaporized at the decreasing pressure due to said at least non-converging passages and said high velocity to attain even higher velocities for more effective entrainment of said gaseous fluid; and being designed to convert to velocity of said motive fluid, energy due to centrifugal action of the rotating impeller and also energy due to pressure differential between the impeller inlet and the impeller outlet; b. a casing disposed about said impeller; said casing having a centrally disposed chamber defined about said impeller for receiving said gaseous fluid; said chamber extending radially outwardly concurrently with said impeller; an inlet port connected with said chamber for intake of said gaseous fluid; a mixing section connected with the circumferential portion of said chamber and encompassing the discharge passage of said impeller for entraining said gaseous fluid from said chamber into the effluent stream of said motive fluid which has unusually high velocity and unusually high efficiency of entrainment as a consequence of its acceleration by said impeller; said casing having a suitable compressing passage providing for the compression and deceleration of the combined fluid stream after said motive fluid leaves said impeller, suitable vanes being provided in said compressing passage to prevent circular motion of said fluid in said compressing passage and to improve compression performance; said casing being provided with inlet and outlet ports, respectively, for connection of suitable respective conduits for the intake of said motive fluid and for the discharge of said compressed gaseous fluid and said motive fluid; and c. a shaft to support said impeller, said shaft having a shaft seal.
 2. The machine of claim 1 wherein the impeller motive fluid passages are diverging to provide for acceleration of the motive fluid due to partial vaporization of said motive fluid in said impeller fluid passages.
 3. The machine of claim 1 wherein the mixing section and the compressing passages in the casing containing the vanes, are made a converging-diverging passage with the position of the vanes being adjustable to provide for optimum performance.
 4. The machine of claim 1 wherein said machine is used as a vacuum pump.
 5. The machine of claim 1 wherein gas acceleration vanes are provided on the outer surface of said impeller intermediate said impeller and the interior walls of said chamber for accelerating said gaseous fluid and for providing an initial velocity to said gaseous fluid so as to move it in the same direction that said motive fluid is moving such that the entrainment of said gaseous fluid is enhanced for improved efficiency in compressing said gaseous fluid by said high velocity motive fluid from said impeller. 